Process of dyeing cellulose ethers



Se t. 14, 1926.

PATENT OFFICE.

EICHWEDE AND ERICK FISCHER, 0F HOCHST-ON-THE-MAIN, GERMANY, AS-

SIGNORS T0 GRASSELLI DYESTUFFS CORPORATION, OF NEW YORK. N. Y., A COR-' PORATION OF DELAWARE.

PROCESS OF DYEING CELLULOSE ETHERS.

{paw-Drawing. Application filed November 9, 1925, Serial No. 68,027, and in Germany November 25, 1924.

It is known that there are only a few acid axe-dyestuffs which yielddeep and fast dyeings on cellulose esters or ethers, for instance on acetate silk.-By far most of these acid azo dyestuffs do not dye them atall or give onlyvery weak dyeings of no practical use. Now we have found that diethylanilinesulfqnic acid and its substitution products,

iwhenroupled with unsulfonated aromatic diazo compounds of the benzene or naphthalene series containing at least one nitro group, yield dyestuffs which give on cellulosegester, for instance acetate silk, deep -itgi nts varying from yellow to violet and possessing good properties as to fastness.

T ie following example serves to illustrate our invention v 1 kg. of acetate silk is dyed for to 1 hour at GOTO in a dye bath of 2025 litres, in which 20- grams of the dyestuff obtained from ,diazotized 3-nitro-2-methyl-1-a1ninobenzene with diethylaniline-m-sulfonic acid are dissolved, with or without the addition of a salt or acid or with or without the addition of'a protective colloid. In this manner a deep golden-yellow tint of excellent properties as to fastness is obtained.

If in the dyestuff, mentioned in the foregoing example, the 3-nitro2-methyl-1-amihob'enzene used as diazo component is replaced, for instance, by 4,-chloro-2-nitro-laminobenzene or l-nitro-Q-aminobenzene-1- carboxylic acid ester or a similar base, deep orange tints of equally good fastness are obtained, whereas the dyestuff obtained for instance from 2.4-dinitro-l-aminobenzene and ,diethylaniline-m-sulfonic acid gives deep in which R represents a benzene or naphthalene nucleus, substituted or not, but containing no sulfo group, and H stands for hydrogen or any substituent.

2 Process of dyeing cellulose ethers, which consists in dyeing these ethers with the monoazo dyestuffs of the following constitution:

NO: CH

3. Asnew products, cellulose ethers dyed with monoazo dyestuffs of the following constitution i SOSH H in which R represents a benzene or naphthalene nucleus, substituted or not, but containing no sulfo group, andH stands for hydrogen or any substituent.

In testimony whereof, we atfix our signatures.

HEINZ EICHWEDE. ERIGH FISCHER. 

